With advances in power electronics and microprocessors, self-controlled synchronous motors are becoming more commonly employed for servo drive applications, not only because of their absence of brushes and commutator but more importantly because their characteristics and controllability are similar to those of conventional dc motors. This paper describes a microprocessor-controlled scheme for an inverter-fed synchronous motor drive, particularly suitable in the 10kW-100kW range. A M68000 micro-processor is used to control a 3-phase GTO-based inverter and a switch-mode field feed system. The control scheme is based on the self-synchronised principle, incorporating a rotor angle sensor.

With advances in power electronics and microprocessors, self-controlled synchronous motors are becoming more commonly employed for servo drive applications, not only because of their absence of brushes and commutator but more importantly because their characteristics and controllability are similar to those of conventional dc motors. This paper describes a microprocessor-controlled scheme for an inverter-fed synchronous motor drive, particularly suitable in the 10kW-100kW range. A M68000 micro-processor is used to control a 3-phase GTO-based inverter and a switch-mode field feed system. The control scheme is based on the self-synchronised principle, incorporating a rotor angle sensor.